CN204392209U - A kind of synchronous sampling signal pre-process circuit - Google Patents
A kind of synchronous sampling signal pre-process circuit Download PDFInfo
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- CN204392209U CN204392209U CN201520086884.7U CN201520086884U CN204392209U CN 204392209 U CN204392209 U CN 204392209U CN 201520086884 U CN201520086884 U CN 201520086884U CN 204392209 U CN204392209 U CN 204392209U
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Abstract
The utility model relates to a kind of synchronous sampling signal pre-process circuit, comprising: input interface, homophase follower, second order Butterworth LPF, signal transformation circuit, optical coupling isolated location, output interface; Signal to be detected for receiving signal to be detected, and is sent to the input of homophase follower by input interface; The output of homophase follower is connected with the input of second order Butterworth LPF by a direct current isolated location; The input of the output connection signal shaping circuit of second order Butterworth LPF; The output of signal transformation circuit is connected with the input of optical coupling isolated location; The output of optical coupling isolated location is connected to output interface.The utility model structure is simple, strong interference immunity, can high order harmonic component signal effectively in filtering power frequency component, contributes to realizing the high-precision synchronized sampling of phase-locked loop, guarantees the synchronized sampling of data to be tested.
Description
Technical field
The utility model belongs to electronic technology field, relates to a kind of synchronous sampling signal pre-process circuit.
Background technology
In the quality of power supply, protection, in the circuit such as measurement, often need to carry out synchronized sampling, namely sampling signal being fixed to frequency in a power frequency cycle is required, the most frequently used method utilizes digital phase-locked loop exactly, digital phase-locked loop needs power frequency component to carry out shaping, generate square wave, as the synchronous sampling signal of AD, and power frequency component is due to the existence of nonlinear-load, high order harmonic component may be comprised, the existence of high order harmonic component, can make power frequency component in a cycle, produce the zero crossing more than normal signal, to the shaping of waveform, the square wave generated just has multiple narrower glitch, interference is caused to phase-locked loop, whole system is even caused normally to work.
Utility model content
The purpose of this utility model is synchronous sampling signal pre-process circuit, solves problems of the prior art.
The technical scheme that the utility model solves the problems of the technologies described above is as follows: a kind of synchronous sampling signal pre-process circuit, comprise: input interface, homophase follower, second order Butterworth LPF, signal transformation circuit, optical coupling isolated location, output interface;
Described signal to be detected for receiving signal to be detected, and is sent to the input of described homophase follower by described input interface;
The output of described homophase follower is connected with the input of described second order Butterworth LPF by a direct current isolated location;
The output of described second order Butterworth LPF connects the input of described signal transformation circuit;
The output of described signal transformation circuit is connected with the input of described optical coupling isolated location;
The output of described optical coupling isolated location is connected to described output interface.
On the basis of technique scheme, the utility model can also do following improvement:
Further, described homophase follower comprises the first operational amplifier;
Described first operational amplifier, its in-phase input end connects the input of described homophase follower, and its output connects the output of described homophase follower, and its inverting input is connected with output.
Further, describedly comprise capacitance every straight unit, described capacitance series connection is between the output and the input of described second order Butterworth LPF of described homophase follower.
Further, described second order Butterworth LPF comprises the second operational amplifier, the first resistance, the first electric capacity, the second resistance, the second electric capacity, the 3rd resistance, the 4th resistance;
One end of described first resistance connects the input of described second order Butterworth LPF;
The other end of described first resistance is connected with the output of the second operational amplifier by the first electric capacity, and this end is connected with one end of the second resistance simultaneously;
The other end of described second resistance is connected with earthing potential by the second electric capacity, and this end is simultaneously by being connected to the in-phase input end of the second operational amplifier;
The inverting input of described second operational amplifier is connected with earthing potential by the 3rd resistance;
The 4th resistance is connected with between the output of described second operational amplifier and inverting input;
The output of described second operational amplifier connects the output of described second order Butterworth LPF.
Further, the capacitance of described first electric capacity, the second electric capacity is 0.45uF; The resistance of described first resistance, the second resistance is 56Kohm.
Further, described signal transformation circuit comprises: the 3rd operational amplifier;
Described 3rd operational amplifier, its in-phase input end connects the input of described signal transformation circuit, and its inverting input connects earthing potential, and its output connects the output of described signal transformation circuit.
Further, described optical coupling isolated location comprises: photodiode and phototriode;
Described photodiode, its anode connects the input of optical coupling isolated location, and its negative electrode connects earthing potential;
Described phototriode, its collector electrode connects the output of described optical coupling isolated location, and its emitter connects described earthing potential;
Described phototriode controls its conducting state by described photodiode.
The utility model sends low pass filter to after power frequency component to be detected is sent into homophase follower, DC-isolation cell processing and carries out low-pass filtering, filter the high order harmonic component signal in signal to be detected, thus disturbing pulse can not be produced, shaping is carried out to filtered signal, and by the one-way transmission of optical coupling isolated location to late-class circuit; The utility model structure is simple, strong interference immunity, can high order harmonic component signal effectively in filtering power frequency component, contributes to realizing the high-precision synchronized sampling of phase-locked loop, guarantees the synchronized sampling of data to be tested.
Accompanying drawing explanation
Fig. 1 is synchronous sampling signal preliminary treatment circuit structure schematic diagram;
Fig. 2 is synchronous sampling signal pre-process circuit one specific embodiment structural representation.
Embodiment
Be described principle of the present utility model and feature below in conjunction with accompanying drawing, example, only for explaining the utility model, is not intended to limit scope of the present utility model.
Fig. 1 is synchronous sampling signal preliminary treatment circuit structure schematic diagram, as shown in Figure 1, a kind of synchronous sampling signal pre-process circuit, comprising: input interface, homophase follower, second order Butterworth LPF, signal transformation circuit, optical coupling isolated location, output interface; Signal to be detected for receiving signal to be detected, and is sent to the input of homophase follower by input interface; The output of homophase follower is connected with the input of second order Butterworth LPF by a direct current isolated location; The input of the output connection signal shaping circuit of second order Butterworth LPF; The output of signal transformation circuit is connected with the input of optical coupling isolated location; The output of optical coupling isolated location is connected to output interface.
Fig. 2 is synchronous sampling signal pre-process circuit one specific embodiment structural representation, as shown in Figure 2, in the present embodiment, homophase follower comprises the first operational amplifier U1, first operational amplifier U1, its in-phase input end connects the input of described homophase follower, and its output connects the output of described homophase follower, and its inverting input is connected with output.Comprise capacitance C0 every straight unit, capacitance C0 series connection is between the output and the input of second order Butterworth LPF of homophase follower.Second order Butterworth LPF comprises the second operational amplifier U2, the first resistance R1, the first electric capacity C1, the second resistance R2, the second electric capacity C2, the 3rd resistance R3, the 4th resistance R4; One end of first resistance R1 connects the input of second order Butterworth LPF; The other end of the first resistance R1 is connected with the output of the second operational amplifier U2 by the first electric capacity C1, and this end is connected with one end of the second resistance R2 simultaneously; The other end of the second resistance R2 is connected with earthing potential by the second electric capacity C2, and this end is simultaneously by being connected to the in-phase input end of the second operational amplifier U2; The inverting input of the second operational amplifier U2 is connected with earthing potential by the 3rd resistance R3; The 4th resistance R4 is connected with between the output of the second operational amplifier U2 and inverting input; The output of the second operational amplifier U2 connects the output of second order Butterworth LPF; First electric capacity C1, the second electric capacity C2 value are 0.47uF in the present embodiment; The value of described first resistance R1, the second resistance R2 is 56K.Signal transformation circuit comprises: the 3rd operational amplifier U3; The input of the in-phase input end connection signal shaping circuit of the 3rd operational amplifier U3; The inverting input of the 3rd operational amplifier U3 connects earthing potential; The output of the output connection signal shaping circuit of the 3rd operational amplifier U3.Optical coupling isolated location U4 comprises: photodiode and phototriode; Photodiode, its anode connects the input of optical coupling isolated location, and its negative electrode connects earthing potential; Phototriode, its collector electrode connects the output of optical coupling isolated location, and its emitter connects earthing potential; Phototriode controls its conducting state by photodiode.
Next, for the circuit of this specific embodiment, the operation principle of the utility model circuit is described:
In this specific embodiment, signal Wave1 to be detected is the 50Hz power frequency component exported by power distribution system source end, this power frequency component is sent to the homophase follower be made up of the first operational amplifier U1, it is high that homophase follower has input impedance, the feature that output impedance is low, decrease the impact on upper level circuit, and the driving force increased rear stage circuit, the power frequency component of the output after the process of homophase follower is through capacitance C0, capacitance CO is logical hands over resistance straight, only AC signal is sent in the second order Butterworth LPF of rear stage, the cut-off frequency of second order Butterworth LPF is:
In the present embodiment,
Therefore cut-off frequency is, meets China's electric power system completely and system frequency is followed the tracks of to the requirement reached.
Second order Butterworth LPF has filtered the high order harmonic component signal in AC signal, therefore disturbing pulse can not be produced, signal is after filtering sent into the signal transformation circuit be made up of the 3rd operational amplifier U3, the shaping of complete pair signals, eventually pass optical coupling isolated location U4 to export, isolate mutually between the input and output of optical coupling isolated location, electric signal transmission has one-way feature, enhance the antijamming capability of circuit, the signal that optical coupling isolated location U4 exports is delivered to phase-locked loop circuit, by the synchronous sampling signal as AD after phase-locked loop circuit frequency multiplication.
The utility model carries out the process such as low-pass filtering to power frequency component, and the high order harmonic component signal in filtering power frequency component, solves the problem that there is glitch in prior art in synchronous sampling signal.
The above implementation step and method only have expressed a kind of execution mode of the present utility model, describe comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the utility model the scope of the claims.Under the prerequisite not departing from the utility model inventional idea, the distortion done and improvement all should belong to the protection range of the utility model patent.
Claims (7)
1. a synchronous sampling signal pre-process circuit, comprising:
Input interface, homophase follower, second order Butterworth LPF, signal transformation circuit, optical coupling isolated location, output interface;
Described signal to be detected for receiving signal to be detected, and is sent to the input of described homophase follower by described input interface;
The output of described homophase follower is connected with the input of described second order Butterworth LPF by a direct current isolated location;
The output of described second order Butterworth LPF connects the input of described signal transformation circuit;
The output of described signal transformation circuit is connected with the input of described optical coupling isolated location;
The output of described optical coupling isolated location is connected to described output interface.
2. a kind of synchronous sampling signal pre-process circuit according to claim 1, is characterized in that: described homophase follower comprises the first operational amplifier;
Described first operational amplifier, its in-phase input end connects the input of described homophase follower, and its output connects the output of described homophase follower, and its inverting input is connected with output.
3. a kind of synchronous sampling signal pre-process circuit according to claim 1 or 2, it is characterized in that: described DC-isolation unit comprises capacitance, described capacitance series connection is between the output and the input of described second order Butterworth LPF of described homophase follower.
4. a kind of synchronous sampling signal pre-process circuit according to claim 1 or 2, is characterized in that: described second order Butterworth LPF comprises the second operational amplifier, the first resistance, the first electric capacity, the second resistance, the second electric capacity, the 3rd resistance, the 4th resistance;
One end of described first resistance connects the input of described second order Butterworth LPF;
The other end of described first resistance is connected with the output of the second operational amplifier by the first electric capacity, and this end is connected with one end of the second resistance simultaneously;
The other end of described second resistance is connected with earthing potential by the second electric capacity, and this end is simultaneously by being connected to the in-phase input end of the second operational amplifier;
The inverting input of described second operational amplifier is connected with earthing potential by the 3rd resistance;
The 4th resistance is connected with between the output of described second operational amplifier and inverting input;
The output of described second operational amplifier connects the output of described second order Butterworth LPF.
5. a kind of synchronous sampling signal pre-process circuit according to claim 4, is characterized in that: the capacitance of described first electric capacity, the second electric capacity is 0.45uF; The resistance of described first resistance, the second resistance is 56Kohm.
6. a kind of synchronous sampling signal pre-process circuit according to claim 1 or 2, is characterized in that: described signal transformation circuit comprises: the 3rd operational amplifier;
Described 3rd operational amplifier, its in-phase input end connects the input of described signal transformation circuit, and its inverting input connects earthing potential, and its output connects the output of described signal transformation circuit.
7. a kind of synchronous sampling signal pre-process circuit according to claim 1 or 2, is characterized in that: described optical coupling isolated location comprises: photodiode and phototriode;
Described photodiode, its anode connects the input of optical coupling isolated location, and its negative electrode connects earthing potential;
Described phototriode, its collector electrode connects the output of described optical coupling isolated location, and its emitter connects described earthing potential;
Described phototriode controls its conducting state by described photodiode.
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CN201520086884.7U CN204392209U (en) | 2015-02-06 | 2015-02-06 | A kind of synchronous sampling signal pre-process circuit |
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CN201520086884.7U CN204392209U (en) | 2015-02-06 | 2015-02-06 | A kind of synchronous sampling signal pre-process circuit |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106953599A (en) * | 2017-03-27 | 2017-07-14 | 长沙云涯电子科技有限责任公司 | Circuit occurs for output-stage circuit and amplitude modulation physiotherapy electrical stimulation signal |
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2015
- 2015-02-06 CN CN201520086884.7U patent/CN204392209U/en not_active Expired - Fee Related
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106953599A (en) * | 2017-03-27 | 2017-07-14 | 长沙云涯电子科技有限责任公司 | Circuit occurs for output-stage circuit and amplitude modulation physiotherapy electrical stimulation signal |
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Granted publication date: 20150610 Termination date: 20190206 |